1. Field of the Invention
The subject invention generally relates to balancing batteries and more particularly relates to a method of balancing batteries for use in an electric vehicle.
2. Description of Related Art
It is well known in the prior art to use all electric automobiles to provide transportation for occupants. Many of these prior art electric automobiles carry several thousand pounds of nickel metal hydride batteries to achieve a long range electric vehicle for every day use by consumers. Furthermore, many of these prior art electrical cars needed to be physically large and heavy to accommodate all of these batteries, such that these cars were not capable of achieving necessary acceleration, handling, performance, and the extended range needed for an electric car to become a feasible option for public purchase and use. Many prior art electric cars that were normal size and not overly heavy would have a very small range, thus reducing the feasibility for large mass selling of such cars to the consuming public. Furthermore, many of these prior art electric cars which used such large batteries had problems with protecting the occupants of the vehicle from the high voltage components necessary to move the car at acceptable speeds comparable to that of a gasoline or diesel internal combustion engine. Furthermore, many of these prior art electrical cars had problems with the prior art batteries staying properly charged and having a generally equal balance of charge available between batteries stored within the electric vehicle.
Generally, the batteries arranged within many prior art electric vehicles attempt to have approximately the same voltage. Thus, balancing of the voltages of all of these batteries was performed at predetermined intervals in many prior art electric cars. Some of these prior art balancing systems used external microprocessor equipment to query the voltages of each battery. Then the processor would send commands to adjust all of the batteries such that all of the batteries had generally the same voltage. However, disadvantages occurred with this prior art system such as the external microprocessor might not be connected to the batteries, hence balancing would not be started or stopped at an appropriate time without instructions from the external microprocessor. This generally might occur after the batteries have been assembled but before installed into the motor vehicle and connected to the external microprocessor controlling the overall vehicle electrical system.
Therefore, there is a need in the art for an improved methodology of self balancing batteries in an electric vehicle. There also is a need in the art for a methodology that will have enable and disable commands available for use by an external microprocessor. There also is a need in the art to have a methodology that will prevent balancing from being permanently disabled, hence only having balancing disabled for a specified time period. Furthermore, there is a need in the art for a self balancing methodology for batteries in an electric vehicle that allows balancing to begin the moment the batteries are connected or disconnected from each other and between other batteries arranged at other portions of the vehicle.